Lac Operon

Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. The lac operon is an operon required for the transport and metabolism of lactose in Escherichia coli and some other enteric bacteria. It consists of three adjacent structural genes, a promoter, a terminator, and an operator. The lac operon is regulated by several factors including the availability of glucose and of lactose. Gene regulation of the lac operon was the first complex genetic regulatory mechanism to be elucidated and is one of the foremost examples of prokaryotic gene regulation. In its natural environment, the lac operon is an complex mechanism to digest lactose efficiently. The cell can use lactose as an energy source by producing the enzyme ß-galactosidase to digest that lactose into glucose. However, it would be inefficient to produce enzymes when there is no lactose available, or if there is a more readily- available energy source available such as glucose.